A United Airlines Boeing 787 diverted to Seattle-Tacoma International Airport Tuesday because of a mechanical issue.

United flight 139, from Denver to Tokyo, diverted "due to an indication of a problem with an oil filter," United spokeswoman Mary Ryan reported. "The aircraft landed normally and without incident and we are working to reaccommodate customers."

The jet landed safely at 4:15 p.m., according to Port of Seattle spokesman Perry Cooper. He said Port of Seattle firefighters found no problems, and the airplane taxied to a gate at the A concourse.

Any potential problems with a 787 attract particular scrutiny, following up on the battery smoke and fire issues that grounded all 787s earlier this year and forced Boeing to redesign the aircraft's battery system.